Feed mechanism



P. H. DIXON FEED MECHANISM May 22, 1956 4 Sheets-Skies;

Filed April 14, 1950 grwc/wfom Paul H. D ixmn wvgzwi/g W P. H. DIXON FEED MECHANISM May 22, 1956 4 Sheets-Sneet Filed April 14, 1950 avvuonfo't 1 11111 H- D ixnn 4/ GWS P. H. DlXON FEED MECHANISM May 22, 1956 4 Sheets-Smear;

Filed April 14, 1950 mew/4 ,UQ A $4M;

P. H. DIXON FEED MECHANISM May 22, 1956 4 ShaetsSneet 4 Filed April 14, 1950 gwuwwfo'v Puul H- D ixmn United States Patent FEED MECHANISM,

Paul H. Dixon, Rockford, Ill., assignor to the United States of America as represented by the Secretary of the'Army Application April 14, 1950, Serial'No. 155,893

9 Claims. (Cl. 89--33) This invention relates to improvements in ammunition feed mechanisms for automatic guns and more specifically to ammunition feed mechanisms utilizing the recoil. energy of the 37 mm. aircraft gun having a. cyclic rate of 500 rounds per minute.

The specific nature of the invention as well as the objects and advantages thereof will clearly appear from the following description and accompanying drawings in which:

Figure 1 is a longitudinal sectional view of the feed. mechanism of this invention positioned on the receiver.

Figure 2 is a horizontal section taken through the housing feed mechanism in plan.

Figure 3 is a. plan view similar to Figure 2, but showing, the feed drive mechanism in section.

Figure 4 is a section taken along 1ine 44 of Figure. 1.

Figure 5 is a section taken along line 5-5 of Figure 1.

Figure 6 is a section taken along line 6-6 of Figure 1.

Figure 7 is a perspective view of the actuating finger assembly.

Figure 8 is a plan view of one of the two ramrncr arms.

Figure 9 is an elevation of one of the two rammer arms.

Figure 10 is a fragmentary sectional view showing the yoke keyed to clutch disc of the feeder control clutch.

Figure 11 is an enlarged detail view showing the sprocket and stripper assembly.

Referring now to the drawings by characters of reference, there is shown particularly in Figures 1, 2 and 3 an embodiment of this invention in which 1 is the barrel of the automatic gun having a breech ring 2 fixed thereto by threads 3 and supporting horizontal diametrically spaced rammer arms 4, all contained in the cylindrical receiver 5. The bolt 6 is shown in counterrecoil position driving a round 7 into the breech 8. Mounted on the receiver 5 and releasably retained thereon by means of a locating bar 9 and latch 10, Figure 1, is a housing or frame 11 in which is mounted the ammunition feed mechanism. The top of the reciprocating breech ring 2 is in the form of a double rack 12 and each driving one of a pair of gears 13 mounted on shaft 14 supported by housing 11 as at 15. One end of the shaft 14 has afiixed thereto a bevel gear 16 in engagement with a bevel clutch gear 17 integral with one element of a driving clutch 18. Driving sleeve is journaled on drive shaft 22 within housing 11. This sleeve has the other element of clutch 18 secured thereto, whereby the sleeve is driven in a corresponding direction of rotation by recoil only of the barrel. A second or holding sprag clutch 19 is mounted contiguous to clutch 18 and acts between sleeve 20 and a sleeve or bracket 26a fixed with housing 11 and acting to prevent reverse or retrograde rotation of the sleeve. The feeder shaft is provided with safety nuts 38. The inner end of feed drive spring 21 is fastened to the sleeve 20 as at 2011 and the outer end is fixed to the spring drum 23 as generally indicated by reference numeral 24. The forward end 25 of the drum bears against a bracket 26a. Drum 23 is journaled for rotation about the axis of shaft 22 and 2,746,357 Patented May 22, 1956 its. rearward end has longitudinal projections 23a. engag' ing slots 28 in the drive sleeve 29 of the escapement clutch 30 having its hub 31 slidably mounted on splines 32 on the corresponding end of feeder shaft 22. A bracket 33 fixed to the housing 11 supports. the rear end of the feeder shaft 22. A stop clutch 34 is, splined on the feeder shaft 22 adjacent the rear end of said shaft and functions to limit the rotation of said shaft to place one round in ramming position during the counterrecoil movement of the barrel. The clutch 3.4 comprises a disc member 35 and. a flanged drum member 37. The disc member 35 is slidably mounted on a spacer sleeve 36 concentric with shaft, 22 and is held in resilient engagement with the drum member by means of. spring 40. The sleeve is retained on said shaft by a safety nut 38 and has one end flanged and in engagement with the drum member 37. Aflixed adiacent to the disc 35. as at 41a, see Figures 4 and 10, to. prevent rotating of said disc, and to limit the rotation of the feed drive shaft, is a yoke 41. The yoke has a forwardly and downwardly extending finger 42 for engaging the stops 39 of the drum 37., said stops being spaced apart. A bracket 43 fixed to the housing 11 by any suitable means. supports a. shaft 45 (see Figure 7) having one of its ends squared at 4.6 for reception, in a similarly-shaped. opening in yoke 41 and its opposite end 47 supporting and fixed to a link 48 having, pivotal engagement with a. lever 4.9. The lever 49 has a stud 50 revolvable in the bracket 43 as at 5.1.. Figure 3. The stud 50. has a head 50a. Pivo ally support: ing an actuating finger 52. The actuating finger 52 engages cam surfaces on the rammer rod 4 to rock the. yoke. 41, causing the. finger 42 to disengage th one of the stops 39 and permit the sprocket 58 driven by feed r shaft 22 to rotate 120 and place a round in ramming position. The rammer rods which assist in ramming a round into the breech of the gun during counterrecoil movement of the breech ring 2 are formed with a vertical wall 53 and an opposing vertical wall 54 as shown in Figures 8 and 9. The forward end of wall 53 is provided with a cam 55 for deflecting the actuating finger 52 vertically and a cam 56 for deflecting the finger horizontally into the groove 57 formed by said walls. The wall 54 forward of the groove 57 is formed with a cam 54a which engages the actuating fing pon recoil and aligns it with the cam 55 for engagement with the cam upon counterrecoil movement. A feeder sprocket 58 having teeth 58a for engaging links 59 of the ammunitio belt 60. is splined to the feeder shaft 22 as at 61, Figure 5, and spaced from the drum 37 by means of spacer sleeve 62. The escapement clutch 30 is spring loaded by means of spring 30a encircling hub 63 of the sprocket, and partially housed in a perforation 69a in the: stripper support 69,. One of the spring ends bears against the sprocket and the other end bears against the flange of the bushing 64 which is in resilient engagement with hub of the escapement clutch. The purpose of the escapement clutch, which is set to slip at a predetermined torque, is to prevent excessive winding of the drive spring 21.

Referring now to Figures 4, 5 and 6 there is shown a round guide 65 mounted on the lower right hand Side of the housing 11 for guiding the projectile of the round into the housing. Attached to the inside of the top of the housing 11 above the guide 65 and forward of sprocket 58 is loading guide 66 in cooperative relationship with guide 65. Also attached to the. inside of the top of housing 11 but rearward of the sprocket is a loading guide '67 for guiding the cartridge case of the round. Pivotally mounted in loading guides 66 and 67 are spring loaded latches 66a and 67a arranged to hold the round in position for ramming after round] has been placed on h round pp rts 80. Two substan iall shaped stripper supports 68 and 69 flankin the spr ck t 58 are provided with clamp-like bases and attached to the lower left hand side of housing 11 as shown by the reference numeral 70. The strippers 71 and 72 are pivoted to the supports 68 and 69, respectively, by means of bar 73 as best shown in Figure 3. The tapered fingers 71a and 72a of the strippers engage the grooves 74 and 74a of the belt clips 60a, wedging the round downwardly to seat said round on the round supports as the belt is pulled by the sprocket through the housing. The strippers are held in normal position for engaging the grooves of the clips by means of detents 75 and 75a in the supports 68 and 69 respectively. Oppositely disposed to the pivoted stripper 71 there is formed in the stripper support 68 a perforation 68a in which is received a flanged bearing bushing 76 concentric with the shaft 22 and housing needle bearings 77 forming a bearing for sprocket 58. Link guides 78 are attached to the left hand side of the top of housing 11 in alignment with the ammunition belt and guide the belt over sprocket 58 and toward the belt deflector 79 which in turn directs the belt away from the gun. It is to be noted that the right and left hand sides of the housing 11 are identical, permitting the feed mechanism assembly to be mounted on either side so that the ammunition belt can be fed from either side.

.In operation a round is positioned in the breech chamber and the bolt closed. The ammunition belt is placed over the strippers and the links on the sprocket as shown in Figure The drive spring having been previously wound sufliciently to bring a round into ramming position after which the energy for feeding is obtained from the recoiling parts of the gun and stored in the drive spring until required. A spring loaded disc clutch referred to herein as an escapement clutch provides an escapement at 700 inch pounds of torque so that the feed drive spring will ,not become broken from excessive recoil winding. As the gun recoils feed drive gears 13 meshed with racks 12 on the breech ring rotate and transmit their motion through bevel gears 16 and 17 to wind the feed drive spring 21. The bevel gears must necessarily oscillate as the gun recoils and counterrecoils. In order to wind the spring in only one direction, sprag clutches 18 and 19 are used between the bevel clutch gear and winding sleeve 20 of the feed drive spring. Sprag clutch 19 prevents the spring from unwinding by engagement of the sprag periphery to the stationary bearing bracket. Clutch 18 engages between the bevel clutch bear 17 and winding sleeve 20 to wind the drive spring during recoil While permitting reverse movement of the gears during counterrecoil. There is also some winding of the feed drive spring after counterrecoil by motion of the parts in the recoil direction from beyond battery position to the batteryposition. The rounds are fed into position by feeder sprocket 58 on drive shaft 22 which engages with the ammunition belt links. Guides 78 retain the belt in position on the sprocket and deflector 79 immediately below the sprocket deflects the belt away from the gun. A stop clutch. 34, positioned to the rear of the sprocket and mounted on the feeder drive shaft, controls the drive spring until a round is required. The stop clutch is released by means of the previously-described linkage including yoke 41 and which is actuated by the cam surfaces on one of the rammer arms 4. As the rammer arms reach battery position, after ramming a round with their counterrecoil motion, this clutch is tripped to release the drive spring 21 and thereby feed another round into the ramming position. As the feeder drive shaft rotates, the finger extension 42 of the yoke positioned on the disc member of the stop clutch is actuated by a cam on the said ramming arm to engage one of the 120 spaced stops on the flanged drum member of the stop clutch. This assures only 120 motion of the feeder drive shaft until the rammer position indicates the requirement of another round. The round is guided into ramming position by two loading guides 65 and 66 and is held against retrograde motion by spring loaded latches in each of the load-' ing guides. The two strippers remove the clips from the 4 round by wedging between the clip and round carried by the clip, as the round is carried into ramming position.

I claim:

1. In an automatic gun having a receiver, a breech ring and round rammers including cams reciprocably supported in the receiver, a feeding means for ammunition mounted on said receiver comprising a housing fixed to said receiver, a drive shaft mounted in said housing, an ammunition-engaging sprocket rotatable with said drive shaft, a helical drive spring and a drum enclosing said spring concentrically mounted on said drive shaft, a Winding sleeve rotatably supported by said drive shaft, said drive spring having one end connected to said winding sleeve and the other end to said drum, winding means operative during recoil and. counterrecoil of said breech ring, directional limiting means mounted on said winding sleeve and interposed between said drum and said winding means to limit the direction of winding, said winding means comprising a rack formed in the top of the reciprocating breech ring, spaced gears in engagement with said rack and mounted on a shaft supported by said housing transversely of said rack, a bevel gear fixed to one end of the last-named shaft, and another bevel gear journalled on said winding sleeve engaging said first-named bevel gear, first sprag clutch means in said last named bevel gear surrounding and rotating said sleeve during recoil movement of said gun, second sprag clutch means carried in said housing and surrounding and locking said sleeve against rotation during counterrecoil movement thereof, indexing means on said drive shaft adjacent said sprocket, and linkage means actuated by the cams on one of said round rammers during counterrecoil movement thereof for operating said indexing means.

2. In an automatic gun having a receiver, a breech ring and round rammers including cams reciprocably sup ported in the receiver, feeding means for belted ammunition mounted on said receiver comprising a housing fixed to said receiver, a drive shaft mounted in said housing, an ammunition engaging sprocket rotatable with said drive shaft, a helical drive spring and a drum enclosing said spring concentrically mounted on said drive shaft, a winding sleeve rotatably supported by said drive shaft, said drive spring having one end connected to said winding sleeve and the other end to said drum, winding means operative during recoil and counterrecoil of said breech ring, directional limiting means mounted on said winding sleeve and interposed between said drum and said winding means to limit the direction of winding, said winding means comprising a rack formed in the top of the reciprocating breech ring, spaced bears in engagement with said rack and mounted on a shaft supported by said housing transversely of said rack, a bevel gear fixed to one end of the last-named shaft, and another bevel gear journalled on said winding sleeve engaging said first-named bevel gear, first sprag clutch means in said last named bevel gear surrounding and rotating said sleeve during recoil movement of said gun, second sprag clutch means carried in said housing and surrounding and locking said sleeve against rotation during counterrecoil movement thereof, indexing means on said drive shaft adjacent said sprocket, said indexing means comprising a clutch having a flanged drum member fixed to said drive shaft and a plate member slidably mounted on said drive shaft and normally in resilient engagement with said flanged drum member, said flanged drum member including stops spaced on the periphery thereof, a yoke keyed to said plate and formed with a forwardly extending finger for engagement with said stops to limit the rotation of said drive shaft, lever pivoted in said receiver and connected to said yoke, said leyer having an actuating finger affixed to one end thereof for engagement with a cam on one of said rammers to disengage said forwardly extending finger from said stops during counterrecoil movement of said rammer.

3. In a feed mechanism for an automatic gun having a receiver and a breech ring reciprocable in recoil and counterrecoil, a round rammer fixed with said ring for reciprocation therewith, a frame fixed with said receiver, a

winding shaft journaled in said frame, a winding sleeve and a spring drum coaxially journaled on said shaft, a drive spring within said drum and having its ends connected with said sleeve and drum, respectively, drive means rotating said sleeve in response to recoil of said breech ring and including a one-way clutch, means preventing retrograde rotation of said sleeve, a sprocket on said shaft for rotation thereby in position to engage an ammunition belt and draw the same transversely across the receiver in response to rotation of said sprocket, means carried by said frame and cooperating with said sprocket to strip rounds of ammunition from said belt in response to movement thereof by said sprocket and to guide the individual rounds into ramming position into the receiver, means associated with said shaft to releasably hold the same against rotation, and means operated by said round rammer to release said releasable means for indexing pf said sprocket.

4. In a feed mechanism for an automatic gun having a receiver and a breech ring mounting a barrel for reciprocation in recoil and counterrecoil in and with respect to said receiver, a frame fixed with said receiver, a feed shaft journaled in said frame, a sleeve and drum coaxially journaled on said shaft, a coil drive spring within said drum and having its ends secured to said sleeve and drum, respectively, means operated by movement of said breech ring to rotate said sleeve and including an overrunning clutch, means operating between said sleeve and frame to prevent retrograde rotation of said sleeve, a slip-friction clutch between said drum and shaft, a sprocket on said shaft for rotation therewith and adapted to engage an ammunition belt and draw the same through said receiver in response to power from said spring, a stop clutch on said shaft for rotation therewith, a yoke journaled on said frame and normally engaging said stop clutch to prevent rotation thereof, a rammer arm fixed with said breech ring for reciprocation therewith in recoil and counterrecoil and having a cam surface, and means journaled on said frame and operated by said cam surface to actuate said yoke and momentarily release said stop clutch, whereby said sprocket indexes a round into said receiver.

5. In an automatic gun having a receiver, a breech ring and an ammunition round rammer supported by the receiver for reciprocation as a unit in recoil and counterrecoil, a frame fixed to said receiver, a drive shaft journaled in said frame, a sleeve and a spring drum coaxially journaled on said shaft, a drive spring within said drum and having its ends fixed to said sleeve and drum, respectively, first means rotating said sleeve and winding said spring by and in response to reciprocation of said breech ring, second means preventing retrograde rotation of said drum under tension of said spring, a slip friction connection between said drum and shaft, a sprocket mounted on said shaft for rotation as a unit therewith and adapted to engage the links of an ammunition belt and draw the same across said receiver whereby cartridges therein are successively moved into loading position, indexing means including a. first part rotatable as a unit with said shaft and a second part pivoted on said frame and normally engaging said first part to releasably stop said shaft and sprocket in predetermined rotational position, and cam means carried by said rammer and operating said second part in timed relation with said breech ring to effect an indexing movement of said shaft and sprocket by an angular distance equivalent to the distance between successive cartridges in the belt.

6. In an ammunition feed component for an automatic gun, a frame, a shaft journaled in said frame and having a smooth portion and a splined portion, a sleeve journaled on said smooth portion, a drum journaled on said sleeve, a coil spring within said drum and having its ends secured to said sleeve and drum respectively, a slip friction clutch having a driving part fixed with said drum coaxially of said shaft and a driven part splined on the corresponding portion of said shaft, a belt drive sprocket splined on the correspondingly splined portion of said shaft, means fixed with said frame and preventing axial movement of said sprocket with respect to said shaft, a spring surrounding said shaft and acting between said sprocket and driven part to urge said parts into frictional contact axiall; of said shaft.

7. A component as recited in claim 6, a stop member splined on the correspondingly splined portion of said shaft and having a plurality of radial projections, the cquiangular spacing between consecutive projections being equivalent to the distance between consecutive cartridges in a belt engaged by said sprocket, a yoke pivoted on said frame on an axis transverse to said shaft and pivotable from a first position wherein a finger thereon is in the path of said projections, to a second position clearing said projections to permit rotation of said shaft, spring means urging said yoke to first position, and cam means for momentarily moving said yoke to second position and then releasing the same.

8. A component as recited in claim 7, and a disc member mounted for axial sliding on and along said shaft and fixed against rotation, said disc and stop members having frictionally engaging faces when said yoke is in first position, said spring means urging said disc member into engagement with said stop member, movement of said yoke to second position separating said faces.

9. In combination with a gun having a receiver, a breech ring mounted in said receiver for reciprocation in recoil and counterrecoil and an ammunition belt comprising pivotally interconnected links each resiliently gripping a round of ammunition, a frame fixed on said receiver, a drive shaft journalled in said frame, a sleeve and a spring drum coaxially journalled on said shaft, a drive spring within said drum and having its ends fixed to said sleeve and drum respectively, first means rotating said sleeve and winding said spring by and in response to reciprocation of said breech ring, second means preventing retrograde rotation of said drum under tension of said spring, a slip friction connection between said drum and shaft, a sprocket on said shaft for rotation as a unit therewith and positioned to engage and draw said belt over and across said receiver under the influence of stored energy in said spring, stop means normally active to prevent rotation of said shaft, means operated by and in response to reciprocation of said breech ring to momentarily release and then re-engage said stop means whereby said belt is indexed a distance between successive rounds, and means carried by said frame to successively strip rounds from said belt in response to feeding movement of the same and to guide the freed rounds into the receiver.

References Cited in the file of this patent UNITED STATES PATENTS 2,366,395 

